United Airlines’ flight attendants union will head to expedited arbitration with the company next week in a last-ditch effort to stop some 689 non-US based cabin crew, including 230 in Hong Kong, from losing their jobs on October 1.The Association of Flight Attendants-CWA wanted the crew relocated to London to ensure they retained their jobs. Some 151 of the 840 originally at-risk staff would retain their jobs as they were eligible to work in the US, but must relocate.Airlines are planning mass…